The pygmy beaked whale was classified as a distinct species in 1991. With only a few dozen sightings in the wild, most information on this species is taken from stranded specimens. It is one of the smallest members of the Mesoplodon genus and it is thought to be endemic to the warm temperate, tropical waters of the eastern Pacific Ocean.

Appearance:

The pygmy beaked whale has a slender, spindle-shaped body. It has a small head, curved mouthline, narrow, sloping forehead and slightly bulging melon. The small triangular dorsal fin is a distinctive feature of this species with a broad base and set well back on the body – some have likened it to the dorsal fin of a harbour porpoise. It has small dark flippers, and the flukes have slightly pointed tips with no visible notch. The head and upper body of females and juveniles is dark olive-brown to grey-brown, while the belly and lower flanks are whitish-grey. Adult males have similar colouration, with the addition of a wide, slanting light brown or whitish band around the body between the head and dorsal fin and extensive scarring on the upper body. Males also have a more developed melon and more strongly curved jawline, with two teeth erupting at the apex of the arch, mid-way along the jaw. Females and young may be confused with other beaked whales with overlapping ranges. Males however can be distinguished by their two-tone colouration, small body size, and triangular dorsal fin.

Behaviour:

Not much is known about the behaviour of pygmy beaked whales as they have rarely been encountered in the wild however confirmed sightings have found them almost always in pairs, or small groups of only a few individuals. As with other members of the Mesoplodon genus they are considered an oceanic, deep water species with similar prey preferences of deep water fish and squid.

Distribution:

Although a stranded specimen was found on a beach in New Zealand, the range of pygmy beaked whales is considered to be restricted to the eastern Pacific Ocean from central California to northern Chile. Pygmy beaked whales are known to be taken as bycatch in the drift gillnet shark fishery off Peru. Other threats may include noise pollution, marine debris – especially the ingestion of plastic bags, and the impacts of climate change. There is no global estimate for this species and the IUCN lists this species as ‘Data Deficient'.